Deposits of calcium carbonate or magnesium carbonate pose a particular problem in water-carrying flowline systems and technical equipment because they can significantly affect the functioning of such systems and equipment over time. Calcium carbonate and magnesium carbonate are commonly also referred to as “scale”. Various descaling agents are known and in use which are capable of dissolving scale in flowline systems and technical equipment via a chemical reaction. However, such agents must be used repeatedly at regular intervals because otherwise the deposits may grow to such an extent that the flowline systems and technical equipment become inoperable. In such a case, typically, complex and expensive repairs are required.
From European Patent Document EP 2 265 158 B1, there is known a supply container for receiving a water-soluble descaling agent, which may be used, for example, in an automatic beverage maker and which has a housing and is supplied with water from a water source. A separate mixture outlet of this supply container ensures that the dissolved descaling agent is discharged into the flowline system so as to produce its desired effect therein. For this purpose, the throughflow principle is used. This means that the water flows from the water inlet to the mixture outlet, passing through and dissolving the quantity of descaling agent that was introduced by the user at one time, and is discharged as a mixture through the mixture outlet into the flowline system.
However, this approach has the disadvantage that the user must initially fill a specified amount of descaling agent and a specified amount of water into the supply container prior to descaling in order to be able to subsequently perform the descaling procedure. Moreover, the described throughflow turns out to be disadvantageous because it cannot always ensure that the water filled into the supply container will actually dissolve the entire amount of descaling agent. Since the chemical reaction of the solution is very much temperature-dependent, fluctuations may have negative effects in this regard. However, incomplete dissolution of the descaling agent may have serious consequences because the desired effect is not achieved to the extent required. Therefore, there is a need to use the descaling agent in very accurately meterable quantities and to provide a stored supply thereof that allows effective descaling of the flowline system over a long period of time. This, however, gives rise to another problem of this known design. Since the supply container is disposed directly in the portion of the flowline system that is also used for preparing the beverages, there is the disadvantage that, in the event that the descaling agent may not have been entirely dissolved during the descaling procedure, any remaining descaling agent is dissolved and can therefore enter the beverage. This is not only disadvantageous for the taste, but rather may have detrimental effects on health.